Cardiac catheter and shunt electrode

ABSTRACT

An elongated tubular catheter having a tube for discharging a liquid into a heart. A body of electrically conductive material is connected to the tube. The body has a passage for carrying liquid from a dispenser into the tube. An electrical plate electrode connected to the body with a line shunts electric current from the heart. The plate electrode is a disposable item having a flexible sheet base. An electrically conductive skin, as an aluminum sheet, is attached to one side of the base.

United States Patent 1191 Bolduc [111 3,807,391 1451 Apr. 30, 1974CARDIAC CATHETER AND SHUNT ELECTRODE [75] Inventor: Lee R. Bolduc,Minneapolis, Minn.

[73] Assignee: Medical Plastics, Inc., Minneapolis,

Minn.

[22] Filed: Mar. 12, 1973 [21] Appl. No.: 340,566

Related US. Application Data [60] Division of Ser. No. 92,767, Nov. 25,1970, Pat. No. 3,720,209, which is a continuation-in-part of Ser. NOS.711,949, March 11, 1968, Pat. No. 3,543,760, and Ser. No. 866,630, Oct.15, 1969, Pat. NO.

[52] US. Cl.. l28/2.05 R, 128/348, 317/2 B [5l] Int. Cl A6lb 5/02 [58]Field of Search..... l28/2.05 R, 2.05 D, 2.06 R, l28/2.06 E, 2 R,303.13, 303.18, 348 R, 349 R, 2 E, 2 M; 317/2 R, 28

[5 6] References Cited UNITED STATES PATENTS 3,473,087 10/1969 Slade128/348 UX 5/1972 Kahn et al l28/2.05 R X 8/l972 Shinnick et al. l28/348FOREIGN PATENTS OR APPLICATIONS 1,033,971 6/1966 Great Britain 128/348Primary Examiner-Dalton L. Truluck Assistant Examiner-Lee S. Cohen 57ABSTRACT An elongated tubular catheter having a tube for discharging aliquid into a heart. A body of electrically conductive material isconnected to the tube. The body has a passage for carrying liquid from adispenser into the tube. An electrical plate electrode connected to thebody with a line shunts electric current from the heart. The plateelectrode is a disposable item having a flexible sheet base. Anelectrically conductive skin, as an aluminum sheet, is attached to oneside of the base.

11 Claims, 2 Drawing Figures CROSS REFERENCE TO RELATED APPLICATIONSThis application is adivision of U. S. application Ser. No. 92,767 filedNov. 25, 1970, now U. S. Pat. No. 3,720,209. Application Ser. No. 92,767is a continuationin.-part of U. S. patent application Ser. No. 711,949filed Mar. 11, 1968, now U. S. Pat. No. 3,543,760 and U. S. patentapplication Ser. No. 866,630 filed Oct. 15, 1969, now U. S. Pat. No.3,642,008.

BACKGROUND OF INVENTION SUMMARY OF THE INVENTION The invention relatesto a catheter andelectrical conductor means for carryingelectricalcurrent from the catheter. The catheter includes a tubularmember and means having a passage and electrically conductiveproperties. A dispensing means discharges liquid throughthe passage andinto the tubular member. The conductor means can be a disposable plateelectrode connected to the means of the catheter tocarry electricalcurrent away from the catheter and liquid flowing throughthe catheter.

IN THE DRAWINGS FIG. 1 is a diagrammatic view of a device having acardiac catheter attached to a plate electrode located under the body ofapatient positioned on a table; and

FIG. 2 is a diagrammatic view, partly sectioned, of the cardiac catheterand plate electrode of FIG. 1.

The disposable .plate electrode shown in FIG. 1 is usable with a patientduring surgery, catheterization and routine electrocardiography toground and provide an alternate electrical. circuit to the patient. Theplate electrode is used to minimize the induction of ventricularfibrillation or multiple extra systoles when an electrical apparatus isconnected to the patient. It is known that alternating current having 60cycle per second frequency, as used in the United States of America, isamong the most prone to cause ventricular fibrillation. The threshold ofventricular fibrillation. with 60 cycle alternating current shocksadministered to human hearts is very low, in the neighborhood of 180microamperes. With a safety factor of 10, it has been found that shocksexceeding 2 microamperes of 60 cycle alternating current are regardedashazardous if delivered directly to the human heart. Human studiesindicate that 60 cycle shocks are 500 to 5000 times more dangerous whendelivereddirectly to the heart rather than the body surface. The verysmall magnitude of the shocks capable of producing ventricularfibrillation may be appreciated in light of the observation that at60.cycles currents less than one microampere cannot be detected throughthe skin. Saline of blood filled cardiac catheters andpacemakerelectrodes are the usual 1 means of gaining electrical access to thehuman heart.

To minimize the electrocution hazards, the voltage difference betweenthe talbe and the patient and the apparatus or device which may beattached directly to the heart or any other part of the body must beeliminated or reduced to less than a few microamperes of current. In thepresent invention, the apparatus is connected to a disposable plateelectrode in surface contact with the skin of the patient to shunt orbypass any electrical current that may flow between the apparatus andthe patients heart.

Referring to FIG. 1, there is shown a patient 300 located on a table301. An electrical apparatus, indicated generally at 302, having anelectrically conductive saline solution 303 is connecteddirectly to thepatients heart 304 and a source of alternating current 305 used tooperate the apparatus. The apparatus 302 comprises an intracardiaccatheter 306. The catheter 306 is an elongated flexible plastic tube forcarrying the saline solution 303 to one of the chambers of the heart304. A coupling 307 is used to connect the catheter to a dye injector311. The coupling 307 has an electrically conductive body 308 of metalor the like carrying an electrically insulative coating or skin 309. Thedye injector 311 may be replaced with a densimeter or other apparatusfor monitoring the condition of the heart. As shown in FIG. 1, a plateelectrode indicated generally at 312 is located-on the table 301 insurface engagement with the back of the patient 300. The electrode 312,shown in FIG. 2, has a substantially flat base 313 of electricallyinsulative material, as cardboard. Secured to one side of the base 313is an electrically conductive skin 314 of aluminum, tin, or similarconductive metal. The-skinand base may be of the same materials as usedin electrodes disclosed in U. S. Pat. No. 3,543,760. An electricalconductor 316, as a line or wire, is connected to a clamp 317. Clamp 317is in engagement with skin 314. The line 316 is secured to the body 308of the connector 307 and thereby electrically connects the fluid orsaline liquid 303 with the electrode 312.

In use, the electrode 312 shunts or shorts away most of the current fromthe heart 304. The line 316 and electrode 312 together have lessresistance to the current than the saline liquid in the catheter 306.The ratio of resistance between the line 316 and electrode 312 togethercompared to saline column in the catheter 306 is between 300 and 500 toI. This ratio depends upon the diameter and/or length of the salinecolumn. Accordingly, the amount of current applied to the heart isreduced by this factor. The plate electrode 312 along with theconnecting line 316 in electrical contact with the saline liquid 303will substantially reduce the incidence of ventricular fibrillation ofthe heart 304.

While there has been shown and described a disposable plate electrodefor use with an intracardiac catheter, it is intended that the electrodecan be used with other electrical apparatus to ground a patient.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. In combination: a cardiac catheter having a tube adapted to carry aliquid to a patients heart, means to supply liquid to said tube,electrode means having an electrically conductive surface adapted toengage an area of the patients body, and electrical conductor meanselectrically connecting the surface of the electrode means with theliquid in the catheter whereby substantially all electric currents areshunted around the heart.

2. The structure of claim 1 wherein: the electrical conductor meansincludes a body having a passage connected to the tube, said body beingmade of electrically conductive material.

3. The structure of claim 2 including: an electrically insulative skinmeans covering the outside of the body.

4. The structure of claim 1 wherein: said electrode means is a sheetmember having an electrically conductive skin.

5. The structure of claim 1 wherein: said electrode means is a sheetmember having a generally flat flexible base and electrically conductiveskin secured to one side of the base.

6. The structure of claim 1 including: clamp means connecting theconductor means to the electrode means.

7. A catheter and electrical conductor means for shunting electricalcurrent away from the catheter comprising: a tubular member having alongitudinal passage for carrying fluid, means having a passageconnected to the tubular member, said passage of the means being incommunication with the passage in the tubular member whereby fluid canflow through the tubular member and body means, said means being made ofelectrically conductive material, electrode means for carrying electriccurrent, and electrical conductor means connecting the means and theelectrode means pense fluid through the passage.

1. In combination: a cardiac catheter having a tube adapted to carry aliquid to a patient''s heart, means to supply liquid to said tube,electrode means having an electrically conductive surface adapted toengage an area of the patient''s body, and electrical conductor meanselectRically connecting the surface of the electrode means with theliquid in the catheter whereby substantially all electric currents areshunted around the heart.
 2. The structure of claim 1 wherein: theelectrical conductor means includes a body having a passage connected tothe tube, said body being made of electrically conductive material. 3.The structure of claim 2 including: an electrically insulative skinmeans covering the outside of the body.
 4. The structure of claim 1wherein: said electrode means is a sheet member having an electricallyconductive skin.
 5. The structure of claim 1 wherein: said electrodemeans is a sheet member having a generally flat flexible base andelectrically conductive skin secured to one side of the base.
 6. Thestructure of claim 1 including: clamp means connecting the conductormeans to the electrode means.
 7. A catheter and electrical conductormeans for shunting electrical current away from the catheter comprising:a tubular member having a longitudinal passage for carrying fluid, meanshaving a passage connected to the tubular member, said passage of themeans being in communication with the passage in the tubular memberwhereby fluid can flow through the tubular member and body means, saidmeans being made of electrically conductive material, electrode meansfor carrying electric current, and electrical conductor means connectingthe means and the electrode means whereby electric power is shunted awayfrom the tubular member.
 8. The structure of claim 7 wherein: saidelectrode means is a sheet member having an electrically conductiveskin.
 9. The structure of claim 7 wherein: said electrode means is asheet member having a generally flat flexible base and electricallyconductive skin secured to one side of the base.
 10. The structure ofclaim 7 including: clamp means connecting the conductor means to theelectrode means.
 11. The structure of claim 7 including: means connectedto the means having a passage operable to dispense fluid through thepassage.